Rodless pump



y 1951 J. c. WATSON 2,551,516

RODLESS PUMP Filed April 21, 1948 2 Sheets-Sheet l J. c. WATSON May 1, 1951 RODLESS PUMP 2 Sheets-Sheet 2 Filed April 21, 1948 Aflorne s Patented May 1, 1 951 UNITED STATES PATENT OFFICE RODLESS PUMP John Clark Watson, San Antonio, Tex.

Application April 21, 1948, Serial No. 22,479

3 Claims.

This invention relates to pumps and has more particular reference to pumps of the type having a reciprocating pump piston which is moved in one direction by a liquid power column and in the opposite direction by spring means and known as rodless pumps.

One object of the invention is to provide a rodless liquid lifting pump in which the pumping device is moved in one direction by a liquid power column and in the other direction by spring means.

Another object of the invention is to provide a rodless liquid lifting pump as above characterized, wherein on the down stroke of the pumping device, the displaced liquid is forced into a chamber carried by the pumping device and compresses the expansion means therein, which expansion means forces the displaced liquid into the liquid column upon release of pressure thereon, thereby raising the height of the liquid column.

Another object of the invention is to provide a rodless pump as above characterized, wherein the liquid displaced during the downward movement of the pumping device is delivered into a chamber containing trapped gas, whereby the gas is compressed so that .on the up stroke of the pumping device, the compressed gas will force the displaced liquid into the liquid column to elevate the same and permit liquid to be discharged therefrom.

Another object of the invention is to provide a rodless pump as above characterized, which will be comparatively simple in construction, strong,

durable, reliable in operation, compact, and light Fig. 1 is an elevational view, with parts broken away, of a pump constructed in accordance with the present invention;

Fig. 2 is an elevational view, with parts broken away, of the lower moving assembly;

Fig. 3 is an enlarged fragmental sectionalside elevation of the plunger cylinder and plungeri Fig. 4 is an enlarged fragmental sectional side elevation of the well tubing and the major portion of the lower moving assembly; and

Fig. 5 is an enlarged fragmental sectional side elevation of the Working barrel and the remainder portion of the lower moving assembly.

Referring now to the drawin s, there is a rodless pump constructed in accordance with the present invention and comprisinga working clearly illustrated in Fig. 5. As there shown, the. working barrel is a tubular member having av threaded upper end which is secured to the lower end of the well tubing II, as by aninternally threaded bushing 15 suitably secured, as by welding, to the lower end of the well tubing H A valve seat I6 is suitably securedin the bottom end of the working barrel l0 and cooperates with a ball valve I! to form a standing upwardly opening check valve.

The construction of the well tubing I l is clearly illustrated in Fig. 4. As there shown, the well tubing is an elongated tubular member having a bushing 15 secured to its lower end and an internally threaded tubular collar I8 secured on its upper end, as by welding, and in which is threadedly received a bushing IS.

The construction of the plunger cylinder [3 is clearly illustrated in Fig. 3. As there shown, the plunger cylinder I3 is open at its upper end and has its lower end threadedly secured in the bushing I 9. The plunger cylinder 13 is of less diameter than the well tubing II, and, preferably, and

as shown, is of the same diameter as the working barrel ID.

The top plunger I4 is slidably mounted within the plunger cylinder l3 for reciprocatory movement therein and comprises a plunger rod 20 having a plurality of leather cup-shaped pumping cups 2 I, each separated by a cup expander 22 mounted thereon. The pumping cups and the expanders are held in place by an upper retaining nut 23 and a lower locking nut 24, both of which are threadedly mounted on the threaded lower end of the pumping rod 2|]. The upper end of the rod 20 is threadedly, detachably connected to a bifurcated rod connection 25 which,

is operated by any suitable means (not shown). The plunger cylinder is provided with a vertically spaced pair of discharge ports 26 adjacent its upper end and positioned intermediate the stroke of the plunger M. It will be understood that the discharge ports are above the level of the. ground and that an ordinary spout or delivery i e may be connected to the cylinder barrel at the ports.

The lower moving assembly [2 is mounted within the Well tubing. Its construction is clearly illustrated in Figs. 2, 4 and 5. As there shown, the assembly comprises an open-ended tubular fluid conduit 21 having a valve cage 28 suitably secured on its upper end. The open upper end of the conduit within the valve cage forms an upper valve seat 29 upon which, and within the cage, is mounted a ball valve 30 which cooperates with the seat to form the top check valve. A cylindrical member 3| is concentrically mounted on the conduit 21 intermediate of its ends, and has its upper and lower ends closed, as by means of annular plates 32, 33, respectively, to form an air chamber 34. The annular plates 32, 33 are suitably secured to the outer walls of the conduit 21, as by welding. The lower portion of the conduit 21 within the air chamber 34 is provided with a plurality of vertically spaced openings 35 communicating with the interior of the air chamber. The outer diameter of the air chamber 34 is less than the inner diameter of the well tubing to permit the flow of liquid therebetween.

A perforated annular plate 36 is slidably mounted on the conduit 21 adjacent to its lower end and rests upon the upper end of the working barrel l (see Fig. 4). A coil spring 21 is slidably mounted on the lower end portion of the conduit 21 between the perforated plate 36 and the annular plate 33. The bottom end of the spring rests upon the perforated plate 36 while the upper end engages a spring guide collar 38 suitably secured to the annular plate 33. The bottom end of the conduit 21 extends down into the upper end portion of the working barrel l0 and has suitably secured thereto, as by welding, a tubular nipple 39 which is of less diameter than the conduit 21. A plurality of leather pumping cups 411, each separated by a cup expander 4!, are mounted on the nipple 39 and held in place by a cup-retaining bushing 42 which is threaded onto the bottom end of the nipple.

A bottom check valve is secured to the lower end of the bushing 12 and comprises a valve housing 43 having a self-contained valve seat 44 with which a ball valve 45, mounted within the housing, cooperates. The cage is suitably secured to a valve ball stop 46 which, in turn, is suitably secured, as by welding, to the bushing 42.

The installation and operation of the device are as follows:

Installation The working barrel and well tubing are mounted in the well and immediately fill with liquid to a level corresponding to the liquid level in the well. Then, the well tubing is filled with liquid. Next, the lower moving assembly, with its air chamber filled with air or gas at atmospheric pressure, is dropped into the well tubing to assume the position shown in Fig. 4, i. 62., with the spring 31 extended and with the perforated annular plate 35 resting on top of the working barrel and the bottom plunger, together with the bottom check valve, inside of the working barrel. When the lower moving assembly is properly positioned the conduit 21 is filled with liquid and the air chamber 34 is filled with liquid from the bottom end plate 33 up to a level above the opening 35. Next, the plunger cylinder is attached to the well tubing. Then, the plunger cylinder is filled with liquid up to the lower discharge port. Then, the top plunger with rod connection attached, is placed in the plunger cylinder, with 4 the lowermost leather pumping cup in contact with the liquid in the cylinder.

Operation The downward movement of the top plunger to the position where the lowermost leather pumping cup is in contact with the liquid at the lowermost discharge port, is the first part of the downward stroke. At this time the top valve, the bottom valve, and the standing valve are closed.

Pressure is applied to the rod connection (by any suitable means, not shown) to force the top plunger downwardly in the plunger cylinder. This results in building up pressure on the liquid column in the well tubing. As the pressure is built up in the liquid column in the well tubing, the lower moving assembly and the bottom plunger move downwardly, thereby compressing the spring 31 below the air chamber 34. As the bottom plunger moves downwardly, liquid passes downwardly through the perforated spring retainer plate 35 from the well tubing ll into the upper part of the working barrel ID above the bottom plunger. The standing valve remains closed as the pressure inside the working barrel below the bottom plunger is greater than the pressure outside of it. The bottom valve opens as the pressure in the lower part of the working barrel between the bottom plunger and the standing valve is greater than the pressure inside the lower moving assembly. As the bottom valve opens, liquid passes upward through the nipple carrying the bottom plunger into the fluid conduit 21, through the ports or openings 35, into the lower portion of the air chamber 34 and compresses the air or gas in the air chamber. This continues until the end of the downward stroke is reached. At the end of the downward stroke. the top valve is closed, the standing valve is closed, and the bottom valve closes from the weight of the valve ball. When the bottom valve closes from the weight of the valve ball at the end of the downward stroke) the pressure inside the lower moving assembly between the top valve and the bottom valve is equal to the pressure in the lower part of the working barrel between the standing valve and the bottom plunger.

At the beginning of the upstroke, the top valve, the bottom valve, and the standing valve are closed. The rod connection is moved upward, pulling the top plunger upward and releasing the pressure on the fluid column in the well tubing and the downward pressure on the bottom plung-- er. As the downward pressure is released, the spring expands, pushing the lower moving assembly upward until completion of expansion of the spring. The bottom plunger moves upward and fluid passes upward from the upper part of the working barrel, above the bottom plunger, through the perforated spring retainer plate into the well tubing. Pressure is also released from the lower part of the working barrel below the bottom plunger, resulting in the pressure inside the working barrel, below the bottom plunger, falling below the pressure caused by the column of fluid in the well outside of the working barrel. As a result, the standing valve opens and the lower part of the working barrel below the bottom plunger fills with fluid from the well until the end of the upward stroke is reached.

The compressed air or gas in the air chamber expands and the top valve opens at the instant the pressure in the well tubing becomes less than the pressure inside the lower moving assembly. As a result, the fluid in the lower part of the air chamber is forced from the air chamber, through the ports therein, into the fluid conduit and discharges upwardly through the top valve into the well tubing. The fluid follows the bottom of the top plunger upwardly until the end of the up-stroke is reached.

At the end of the up-stroke, the top valve closes from the weight of the valve ball, the bottom valve is closed, and the standing valve closes from the weight of the valve ball.

On the first part of the next down-stroke, the top valve, the bottom valve, and the standing valve are closed. As the plunger moves downward (it passes above the discharge ports on its upward stroke) the plunger forces the fluid in the plunger cylinder out through the discharge ports until the lowermost leather pumping cup passes below the lower discharge port. During this portion of the downward stroke, all the valves are closed. In the continued operation, the cycles of up and down strokes, as described, are repeated.

From the foregoing it readily will be seen that there has been provided a rodless pump adapted to lift liquid out of deep or shallow wells, in which the pumping device is moved on its down stroke by a liquid power column and on its upstroke by a spring, with the liquid displaced on the down stroke being forced into a chamber filled with trapped gas, whereby the gas will be compressed and, on the up stroke, when the pressure on the liquid power column has been relieved, the gas will expand and force the displaced liquid into the liquid column, thereby elevating it to permit liquid to be discharged therefrom.

While a power plunger piston has been shown as the means for applying pressure to the liquid column in the well tubing, obviously, other means may be employed to apply this pressure.

Obviously, the invention is not restricted to the particular embodiment thereof herein shown and described. Moreover, it is not indispensable that all the features of the invention be used conjointly, since they may be employed advantageously in various combinations and sub-combinations.

What is claimed is;

1. In a well pumping apparatus, in combination, an elongated well tubing having an upwardly opening check valve in its lower end adapted to be submerged in the well liquid and having a liquid outlet adjacent its upper end, said tubing being normally filled with liquid up to said outlet to form a liquid power column, a reciprocatory pumping assembly mounted in the lower end of said tubing above said check valve, said assembly including a chamber containing expansion means and connected to receive displaced liquid; means for applying pressure on said liquid power column to move said pumping assembly downwardly in said tubing to force the displaced liquid into said chamber, thereby compressing the expansion means therein; means for moving said pumping assembly upwardly in the tubing with the displaced liquid trapped in said chamber; and valved means carried by said assembly and cooperatin with said chamber to permit the compressed expansion means therein to expand and expel the displaced liquid from said chamber into the liquid power column as soon as the pressure on the liquid power column is relieved, thereby raising the liquid power column and permitting liquid to be discharged through the liquid outlet.

2. In well pumping apparatus as set forth in claim 1, wherein the pressure on the liquid power column is provided by a reciprocatory plunger piston mounted in the upper end of the well tubing and having a stroke extending above and below the liquid outlet and wherein spring means are provided for moving the pumping assembly upwardly and wherein the expansion means contained in the chamber comprises trapped gas.

3. In well pumping apparatus in combination, a well tubing having a reciprocatory piston in its upper end and a liquid outlet intermediate the stroke of the piston, an upwardly opening check valve in the lower end of the well tubing and adapted to be submerged in the well liquid; a reciprocatory pumping assembly in the lower end of the well tubing, said assembly including a tubular liquid conduit having a check valve at its upper and lower ends, a chamber containing trapped gas and communicating with said conduit intermediate its ends and a piston mounted on the conduit below the chamber; a liquid column in the well tubing extending from the lower piston up to the upper piston and forming a liquid power column connecting the two pistons whereby when the piston in the upper end of the well tubing moves downwardly the pumping assembly will be moved downwardly and the displaced liquid will be forced into the chamber compressing the gas therein; and spring means adapted to be compressed on the downward movement of said assembly for moving said assembly upwardly when the piston in the upper end of the well tubing moves upwardly, whereby the assembly with the chamber containing the displaced liquid wil1 be moved upwardly and the displaced liquid will be expelled from the chamber into the liquid power column when pressure on the column is relieved, whereby the height of the liquid column will be raised to permit discharge through the liquid outlet.

JOHN CLARK WATSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Date 

